Pressurized chain saw oiling system



E. C. KIEKHAEFER PRESSURIZED CHAIN SAW OILING SYSTEM Aug. 5, 1952 Filed Dec. 17, 1948 2 SHEETS- SHEET 1 INVENTOR. /me

Aug. 5, 1952 Filed Deo. 17, 1948 E. C. KIEKHAEFER PRESSURIZED CIIAIN SAW OILING SYSTEM 2 SHEETSf-SHEET 2 Patented Aug. 5, 1952 UNITED STATES PATENT OFFICE Y V. asomar' 'I I v rnEssUnizED onAiN saw onine sifsfrliivir Eimer Vcan insinuaare,(nearing,4 Wis.

f Y Appucaaoaneembef 1v, i948,` serial Ne. casca sfoiaims; (ci. 14s-a2)A This invention 'relates to pressure lubricating systems for engine-driven chain saws for delivery of oilto the rsaw chain during operation of the engine.` I

principal object Yof the inventionis tow provide for thepositive and kenicient delivery ofY oil from a reservoir to thesaw chain. Y `k Another' object is to eliminate lthe*discharge of vexcess oil, from the engine and utilize the oil in the saw chain lubricating system.` y l Another object is to provide for the positive ow of oil under pressure from the reservoir carried by thesaw to the chain to lubricate the same atalltinies during the operation of the saw in any cutting position. Y These andother objects and ladvantages willr be more A fully setiorth in the following descrip-'I` tion of a preferred embodiment of the invention illustrated in the accompanying drawings. n Y

In'the drawings: Y v y c IFigure l is aperspective View or" a chainsaw with parts broken' away to show the'oil reservoir and conduit; n Y ,If

n Fig. 2 is a diagrammatic View ofjth'e'reservoirv with one wall thereof broken away and showing the: operation of the oiling ineans;," v. ""FigfSfis'a perspective lview, o f the reverseside civ-the reservoir; y Y n' 'Y Y j Fig. 4 isfa detailed View partly in section of the oil pick-up to s'howthe construction thereof; and

Fig'. 5 isa'detailed View showing the reservoir tilted in one direction. Y

The 4chain saw shown in the drawings is simi lar to that disclosed andclaiined in the application of the present inventor iiled October 7, 1948, Serial No. 53,261, for EngineDriven Chainsaw, and includes vthe chain I carried bythe guide rail E, the engine 3 having a transmission case carburetor, not shown, linto the crankcase 8.

During the downward power stroke of piston 'I within cylinder 6 the mixture iscompressed within chamber 8 prior to transfer to the upper/end of cylinder il for the next cycle of operation.

The invention contemplates the utilization of the intermittent compression obtained in the crankcase 8 of engine 3 to deliver lubricant to the saw chain.

1 2 v The reservoir l9 containing the oil IilY is ldisposed near the chain` beneath engine 3 and comprises a cast member I I removably secured to one side of transmission case 4 by means of bolts I2.` The wall I3 cast integrally within member II near one end thereof forms a small reserve chamber I4 asrwill be described. v

The flexible conduit I5 connects the fitting I6 at the other end of member II'with the check' valve fitting II on crankcase 8 to allow ythe gas under the pressure developed in the'crankcase during one cycle of engine Aoperation to partly pass into reservoir. The pressure within reservoir S is retained during the opposite cycle of the engine by the check valve fitting Il'. In the continued operation of engine 3 a pressure substantially equivalent to the maximum pressure obtained within crankcase 8 is maintained in reservoir 9.

The `oil pick-up assembly I8 includes the threaded tube I9 extending through chamber I4 into reservoir 9. The exible conduit 20 carries the' oilstrainer 2| at one end and is connected at its opposite end to the inner end of tube I9. The outer end of tube I9 vis closed and carries the head 22 by whichfthe assembly I8 may be re-I moved for draining or filling of the reservoir and cleaning of strainer 2l. The drilled holes 23 in either side of'tube IS'provides for the passage of oil Ifrom reservoir 94 through the pick-up assembly to the reserve chamber I. Other means, not shown, may also be provided for convenience -inilling of the reservoir.

Assembly iii is arranged within reservoir S relative lto the chain saw so that the strainer ZI and thefree end of .Conduit 20 can move gravitationally within the reservoir and with the oil contained `therein to any-of the normal cutting positions of the saw to assure the iow of oil therethrough from reservoir 9 at all times during normal operation. The reserve chamber I4 is maintained full rof oil at all times when in normal positionfby the voil pick-up assembly until the Voil in reservoir r9 is completely'exhausted so that during temporary periods of changing the position of operation of the saw the continuous uninterrupted supply lof oil to the nozzle and the chain is assured.

The nozzle 24 is carried by the transmission case 4 to direct-a stream of oil to the chain. The passage'25 may be provided, as shown, by casting the same within the body of the transmission case II to connect chamber I4 and nozzle 24 for delivery of the oil to the nozzle and chain as described.

The now of oil I0 to nozzle 24 from reservoir! begins automatically with the starting of engine 3 and the developing of the pressure Within the reservoir. When the engine is stopped the pressure returns to normal shortly thereafter so that the flow of oil to the chain is discontinued automatically When not required.

The device is easy to install and maintain and is not subject to mechanical failure. The device employs nomoving parts to wear out or require replacement and is simple and inexpensive to manufacture as a part of or as an accessory to any two-cycle engine-driven chain saw of the type described.

Transmission case 4 forms one side of reservoir 9 closing the same. By removing bolts 22, member I l is easily removed and completely open on one side for inspection.

The fuel employed in the type of engine described includes the engine lubricant which is mixed with the combustion fuel and passes through the engine torlubricatethe same` The excess fuel accumulating in crankcase 8 is in greater part the lubricant which is not passed into cylinder 5 for combustion.

By locating check valvefitting il near the bottom of crankcase 8 as shown in Fig. 2, as for the normal position shown in Fig. 1, the chain lubricating system described, further serves to drain the crankcase of excess accumulated fuel and the excess fuel serves to lsupplement the supply carried in reservoir 9 sov that no oil is wasted and the saw may be operated for longer periods without refilling the reservoir.

Various embodiments of the invention may be carried out within the scope ofthe accompanying claims.

I claim:

1. 1n a. lightweight, portable chain saw unit including a saw chain and an engine vdriving said chain, said engine having a crankcase for induction and precompression of the lubricant and carbureted fuel; a tank -for mixed liquid fuel and lubricant connected to .the engine for induction 'of the fuel for combustion and the lubricant in excess supply to assure full lubrication of the Working parts of the engine, said `crankcasebeing disposedto receive and collect the excess supply of lubricant from the fuel-lubricant mixture delivered to the engine Yfrom said tank, alubricant reservoir, a discharge nozzle connected to said reservoir and directed toward rthe chain for; 'ap-- plying lubricant thereto, and. passage means .non necti-ng said crankcase and Vsaid reservoir disposed to effect transfer of said excess .supply of. lubricant to saidreservoir and maintain iii-said reservoir pressure substantially vequivalentto the maximum pressure conditions within said crankcase-for delivery of the lubricant from Vsaid reservoir'to'th'echain.

2. In a lightweight, portable chain saw unit operable in several positions'andincluding va .saw chain and anY engine driving said chain, said engine `having `a crankcase for induction and precompression ofthe lubricant and carbureted fuel, a .tank for mixed fuel and lubricant connected to the engine for delivery thereto of `fuelfor combustion and lubricant in excess supply to assure fully lubrication of the working parts of the engine, said 'crankcase being disposedto receive and -collect an excess supply of .lubricant from the fuel-lubricant mixture delivered to the engine from said tank, a reserve chamber, a discharge nozzle connected to said chamber and directed toward the chain for applying lubricant thereto, a lubricant reservoir, a, flexible conduit having a free open end movable within parts of said reservoir and communicating at the other end with said reserve chamber, said discharge nozzle and the part of said reservoir beyond the range of lthe free end of said conduit being relatively disposed whereby delivery of lubricant to said nozzle and the chain is provided from said reserve chamber while the lubricant Within said reservoir is outside the range of said conduit, and passage means connecting said crankcase and said reservoir disposed to effect transfer of the excess lubricant to said reservoir and maintain in said reservoir and reserve chamber pressure substantially equivalent to the maximum pressure conditionswithin said crankcase for delivery of the lubricants from said reservoirv to the chain.

3. In a lightweight, portable chain saw unit adapted for use in all positions and including a saw chain and an engine driving said chain, said engine having a crankcase for induction and pre-compression of the lubricant and carbureted fuel; a tank for mixed liquid fuel and lubricant connected to the engine for induction of the fuel for combustion and the lubricant in excess supply to assure full .lubrication of the working parts of the engine, said crankcase being disposed to receive and collect theexcess supply of lubricant from the fuel-lubricant mixture delivered to the engine from said tank, a lubricanty reservoir, a discharge nozzle connected to anoutlet for said reservoir and directed toward the chain for applying lubricant thereto; a flexible conduit within said reservoir and connected at one end to the outlet therefor and having its other end free to move within said reservoir VVand submerged in the lubricant therein for the principal operatingr positions of the saw, and passage means connecting said crankcase and said reservoir disposed to effect transfer of said excess supply of lubricant to said reservoir and maintain in said reservoir pressure substantially equivalent to the maximum pressure conditions withinsaid crankcase during operation of said engine fordelivery of the lubricant from `said reservoir to the chain.

E. .CARLKIEKHAEFER REFERENCES CITED Thefollowing references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 821,915 Altham 'May 29, 1906 904,132 Johnston Nov. v17, 1908 1,385,250 Gernandt July 19, 1921 1,791,045 Stevens Feb. 3, 1931 1,903,571 Meyer Apr. 11, 19,33

2,184,461 vMall Dec. 26, 1939 2,391,730 Melvin et al. Dec. 25, 1945 2,409,775 Mall et al. Oct. 22, 1946 FOREIGN PATENTS Number Country Date 256,067 Great Britain Aug. 5, 1926 

